The average yard contains 10 times more chemicals per acre than a typical commercial farm, according to Consumer Reports. You can make your lawn less toxic by skipping the nitrogen-rich, fast-releasing fertilizer. Instead, mulch grass clippings when you mow and apply compost once or twice per year.
But what about the weeds that can ravage a yard, especially during the summer? Thick, healthy turfgrass is the best defense because it won’t allow weeds to take root. Overseeding thin spots in the lawn will help maintain a thick carpet. In garden beds, a layer of mulch, whether bark chips or mulched leaves, will keep weeds down and retain moisture in the soil.
Even with those precautions, some weeds are bound to infiltrate your property. Blasting them with Roundup isn’t the best idea because the health effects of glyphosate, an active ingredient, and other herbicides like it aren’t fully understood. (The International Agency for Research on Cancer, a division of the World Health Organization, recently determined that glyphosate is a probable carcinogen.)
Consumer Reports offers a list of four common weeds that plague homeowners, along with chemical-free measures that should be effective in bringing them under control. For more information, go to the websites of Beyond Pesticides and the Great Healthy Yard Project.
Dandelion
What is it? A perennial weed whose common yellow flowers turn to windblown seed.
Telltale signs. Though a handful of dandelions is no big deal, a lawn that’s ablaze in yellow has underlying problems that need to be addressed.
How to treat. Like many broadleaf weeds, dandelions prefer compacted soil, so going over the lawn with a core aerator (available for rent at home centers) might eradicate them. It also helps to correct soil imbalances, especially low calcium.
Crabgrass
What is it? An annual weed with a spreading growth habit. It’s common in the Northeast, in lawns with poor soil conditions.
Telltale signs. Lots of bald spots, especially after the first freeze, when crabgrass dies off.
How to treat. Have your soil tested. Lime or sulfur may be needed to adjust the pH. Aeration is also recommended. Corn-gluten meal, applied in early spring, can be an effective natural pre-emergent herbicide.
Advertisement
Barberry
What is it? An invasive shrub with green leaves and yellow flowers, often found in yards near wooded areas.
Telltale signs. Left unchecked, the shrub’s dense thickets will start to choke off native trees and plants.
How to treat. Cut back the stems and paint their tips with horticultural vinegar or clove oil (repeated applications may be needed). Burning the tips with a weed torch might also work.
Fig buttercup
What is it? A perennial weed with yellow flowers and shiny, dark green leaves. It’s common in many parts of the East, Midwest, and Pacific Northwest.
Telltale signs. The weed will start to crowd out other spring-flowering plants. It can also spread rapidly over a lawn, forming a solid blanket in place of your turfgrass.
How to treat. Remove small infestations by hand, taking up the entire plant and tubers. For larger outbreaks, apply lemongrass oil or horticultural vinegar once per week when the weeds first emerge. It might take up to six weeks to eradicate.